Well, I signed up, even though I don't enjoy reading of a back lit screen. But I figured I give it a try for 90 days. I only have the 2012 8.9 inch Kindle FireHD, so its a bit heavy for reading. I don't have any other tablet. I found the app to be a big laggy. Changing pages is quite jerky, but I get used to it.
The spacing is ok for me, but it doesn't do 2 columns, so its a bit cumbersome to read on a 8.9 screen. I think it would be better on a 7 inch tablet, but I don't have one.
I started reading a book and I am going to stay with it to see what I can get out of this. It really is nice for readers of romance, lots of options there so that is a huge plus for me. I notice I read a lot slower though on my fire than on my e-ink kindle. And again, its so heavy.
We'll see how it goes. Its a nice long enough free time to really give it a trial run.
So thanks for posting that offer.
eta: Just had to add that the app eats my battery like crazy. And that is with wifi off. I barely able to read 25% of the book and it went from 70% to 15%. Wowzer.